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Two identical cyclists ride past each other with constant velocities Va and Vb, which are close to the speed of light. Can it be that cyclist A perceives cyclist B as shorter or longer that cyclist B percieves cyclist A ? Or simply La is NOT equal to Lb ? (La-length of cyclist A as seen by cyclist B, Lb -length of cyclist B as seen by cyclist A).

Relevant formulas:

Relative speed V = Va+Vb/(1+(Va*Vb/c^2))

Relative length l = lo * square root from 1-(V/c)^2

Conclusion:

The V from the second equasion is equal for both cyclists, since addition and multiplication are alternate. lo is also equal. So there is no difference in the way cyclists A and B see each other.

Is this conclusion right?

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# Relativistic length, 2 viewpoints

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